Problem syncing up large files

Hi,

I'm having problems syncing back up to my Yahoo Mail a number of emails which are larger than 10 MBs and one that's a shade under 10. They all came from my Yahoo Mail account (I'd accidentally downloaded and wiped from the server back in POP mode), but must've come from back in the day when Yahoo didn't have the 10 MB message size limit. However, now that Yahoo Mail now accommodates messages up to 25MB, I tried syncing them back up through Zimbra Desktop again to no avail. I get the same error message I got several months ago before the change in size limit (see below). Is Zimbra restricting the size limit? If so, can I override some settings like this wiki entry says to do for ZCS? I'd rather not have to install and reinstall any programs if possible as I just need these few files back into my Yahoo account (this issue would all be moot if Yahoo gave free IMAP access to folks, but that's for another day...)Thanks so much for any help. Zimbra rocks.